The device doesn't actually start making its way to customers until April 24 at the earliest, but Kuo believes that more than 2 million people globally have coughed up to get their hands on the device.

If Kuo's figures are correct, Apple has — in a stroke — cornered the entire smartwatch market.

Google has lost the one thing it had going for it

The Apple Watch's strong sales are bad news for Google and its Android Wear smartwatch operating system OS. According to Canalys, devices using Android Wear sold 720,000 units in 2014. Slice's figures suggested Apple was able to easily breeze past this figure in a single day. In doing so, Apple took away Google's one historical advantage, which Business Insider explained in a previous story:

The iPhone has always — with some truth — been considered the "rich man's phone." Apple customers tend to be better off than Android users and spend more on apps and in-app purchases. Accordingly, ad rates on iOS, Apple's operating system, are higher than on Google's OS.

This means that iOS is, at least on paper, the more lucrative platform to develop for. But many developers still choose to go "Android first." Why? Because what Android customers lack in purchasing power (on average), they make up for in sheer numbers. In 2014, Android manufacturers shipped a staggering 1 billion smartphones. That's a milestone that will take Apple years to reach — in the same period, despite having the most profitable quarter of any company ever, the Cupertino company had (relatively) paltry sales of 192.7 million.

This truly massive reach is what makes Android such a compelling platform for developers.

But now, the opposite is true — Apple has the bigger platform (by a massive margin), while Google is the underdog. But unlike Apple, Google doesn't have the wealthy user base to encourage developers to prioritise developing for its OS. (We don't yet have demographics on Apple Watch customers, so we don't know for sure that they are (on average) wealthier. But given the high price point of the Apple Watch — topping out at $17,000/£13,500 — it is a fairly reasonable assumption to make.)

Apple has undercut every rival

A shopper perhaps about to place one of the 2.3 million Apple Watch preorders.AP

This strong push is immediately going to make Apple's Watch OS an extremely attractive platform for developers looking to move into wearables, especially when coupled with the purchasing power of Apple consumers. And as this app ecosystem develops, it will make the Apple Watch even more attractive compared with other smartwatches, consolidating Apple's position further still.

Here's the relevant part of the research note from Kuo at KGI Securities, courtesy of MacRumors (emphasis ours):

We estimate production of Apple Watch around 2.3mn units in March-May. Mass production of Apple Watch began in March and will likely reach 2.3mn by end of May. Considering that most consumers who preordered will not get the device until June, we estimate global preorders of over 2.3mn units, with Apple Watch Sport, Apple Watch and Apple Watch Edition representing a respective order allocation of 85%, 15% and less than 1%.